add vendor directory

vendor/github.com/ugorji/go/codec/codecgen.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2012-2020 Ugorji Nwoke. All rights reserved.
+// Use of this source code is governed by a MIT license found in the LICENSE file.
+
+//go:build codecgen || generated
+// +build codecgen generated
+
+package codec
+
+// this file sets the codecgen variable to true
+// when the build tag codecgen is set.
+//
+// some tests depend on knowing whether in the context of codecgen or not.
+// For example, some tests should be skipped during codecgen e.g. missing fields tests.
+
+func init() {
+	codecgen = true
+}